This is it for Nate Allen. Or is it? Who really knows anymore? The code won’t be cracked until 6 p.m. Saturday, when the roster is trimmed to 53 and the fates of some 22 players are decided by Chip Kelly and his coaching staff.

Maybe then we’ll really know if Allen successfully won his campaign to stave off hard-charging rookie Earl Wolff to start at free safety, the last of the 25 starting jobs still allegedly up for grabs going into Thursday night’s preseason finale against the Jets (see storylines).

Allen and Wolff are both expected to play. It’s unknown -- at least by the media -- whether they’ll alternate per series, like they did last Saturday against the Jaguars, or if Kelly and defensive coordinator Billy Davis have another trick up their sleeves.

It’s feasible to assume that Allen’s roster spot is in jeopardy if he’s outperformed by Wolff. It’s also feasible to think the coaches have already made up their minds and Thursday night’s game is a mere formality.

“You can’t sit there and worry about it and make your nerves go crazy,” Allen admitted. “Then you go out there and play terribly.”

Wolff’s roster spot is secure, but few fifth-round rookies get an opportunity like this: a chance to start the first professional game of their careers.

“I wouldn’t necessarily say nerve-racking,” Wolff said. “I find I learn faster than the coaches thought I would, so I just come out here every day to compete. I know I could play in this league, and I just want to show that I can.”

This much is obvious: Wolff represents the future of the Eagles’ secondary, if he can cement the job and then mature and develop enough to keep it going forward.

If Allen, a fourth-year pro coming off two lousy seasons, had already convinced the staff that he’s back to the form of his rookie year, before a torn patellar tendon derailed his career, then he wouldn’t be squaring off against Wolff in a meaningless exhibition.

The fourth preseason game for Allen is as much about putting his best stuff on tape for the 31 other teams as it is for Kelly’s roster decisions. Even if he makes the team this year, Allen almost certainly will be unemployed at year’s end.

“You’ve got to compete every year,” said Allen, denying that he’s disappointed to be playing in the fourth preseason game at this stage of his career. “Every day you go out there competing for a job.”

Wolff has already demonstrated rare poise for a third-day rookie. No other rookie on defense earned first-team snaps during the spring camps and no other defensive rookie is still fighting right now to be among the starting 11.

Wolff even knows the right people to attach himself to, tapping into the mind of franchise icon Brian Dawkins for pointers.

“Even when Brian Dawkins came out to practice, I asked him to come out there and check me out, and he said I need to train my eyes a little more and make sure my eyes are in the right spot,” Wolff said. “And it all starts with practice. And if you do it in practice, then it happens in the game, so right now that’s really what I’m trying to do.”

Wolff, whose family is from Philly, sought Dawkins’ advice earlier this spring when he spotted the legend roaming around at practice.

“Man, it means a lot,” he said, “because coming here … I’ve always watched him, you know, and when I came here and finally got to talk to him and he told me to take down his contact information so any time I have a question about football or even life, I can talk to him about it.”

Is Weapon X on speed dial?

“I try not to call him all the time,” Wolff said. “I’ve talked to him once or twice, not too much.”

Wolff could have used Dawkins’ insight Saturday against Jacksonville before taking an indirect route to Jordan Todman that enabled the little-known (unknown?) Jags tailback to burst free and scamper 63 yards for a touchdown.

But he handled the questions afterward with savvy and poise, accepting blame and promising to bounce back. It’s clear he doesn’t let the moment get too big and he won’t be overwhelmed by Thursday night’s final audition.

“The thing is, if I think about it like that, then I might try to do too much,” he said. “So I’m just going out there thinking about playing my game and thinking about playing the game of football that I love to play.”